Nitrous oxide provokes changes in folylpenta- and hexaglutamates.
Liver folates isolated from rats fed a control diet consisted of H4PteGlu5 (44% of total) and 5-methyl-H4PteGlu5 (19%) with smaller amounts of 10-formyl-H4PteGlu5 (13%), H4PteGlu6 (13%), 10-formyl-H4PteGlu6 (4%) and 5-methyl-H4PteGlu6 (2%). Folates from methionine-deficient rats contained more nearly equal amounts, on a molar basis, of folylpenta- and hexaglutamates, and hence these were more suitable subjects for comparing the metabolism of these compounds in vivo. Livers from methionine-deficient rats contained H4PteGlu5 (30%), 5-methyl-H4PteGlu5 (13%), 10-formyl-H4PteGlu5 (10%), H4PteGlu6 (22%), 5-methyl-H4PteGlu6 (9%) and 10-formyl-H4PteGlu6 (11%). With exposure to N2O, 5-methyl-H4PteGlu5 and 6 increased to 27% and 13%, respectively, whereas H4PteGlu5 and 6 decreased to 20% and 17%, respectively. Nitrous oxide (N2O) perturbed both the penta- and hexaglutamates; the effect was somewhat more pronounced with the pentaglutamates. The partial depletion in tissue H4PteGlun with N2O treatment helps explain the concomitant inhibition of the oxidation of [ring-14C]histidine, an event dependent on tetrahydrofolates.
Brody
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Department of Nutritional Sciences, University of California, Berkeley 94720.
Stokstad
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D000818:Animals; D002848:Chromatography, DEAE-Cellulose; D004044:Dietary Proteins / Q000008:administration & dosage*; D005492:Folic Acid / Q000031:analogs & derivatives*; D006639:Histidine / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000172:deficiency; D009609:Nitrous Oxide / Q000494:pharmacology*; D011624:Pteroylpolyglutamic Acids / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D004044:Dietary Proteins; D011624:Pteroylpolyglutamic Acids; D006639:Histidine; D005492:Folic Acid; D008715:Methionine; D009609:Nitrous Oxide